Traditionally, the power limit to the central processing unit (CPU) has been provided by the platform. With the advent of integrated memory controllers, the CPU or processor controls the power consumption of the memory modules in the platform as well. In a micro-processor based platform, the power consumption of the memory modules in the platform can constitute a significant portion of the total power consumed by the platform.
In many platforms, the processor and the memory modules are treated as separate power domains when the total platform power budget is allocated. When the total platform budget such as platform rating is determined, each domain is set to a realistic maximum value, which is not the worst case scenario. As such, there is a processor power limit that is obeyed by the processor and a memory power limit that is obeyed by the memory modules.
When the memory modules and the processor each have a separate power budget or limit, it limits the performance of the platform or system for low-bandwidth workloads.